Internet Protocol (IP) security is technology in which the IP, which is a network layer, provides security. The IP security includes protocols such as an Encapsulating Security Payload (ESP) that together supports an authentication header that allows authentication of a data transmitter and data encoding and authentication of a transmitter. The IP security provides a tunnel mode that provides a security tunnel between security gateways and a transport mode that provides a security tunnel between termination hosts.
The IP security may be applied to a Voice over Internet Protocol (VoIP) service. In this case, messages of a Session Initiation Protocol (SIP) for setting the VoIP call may be processed according to the IP security. Typically, when a commercialized Long Term Evolution (LTE) system provides the VoIP service, a terminal uses a plurality of TCP/IP stacks. Each TCP/IP stack may be controlled by different processors. In this case, when IP security is applied, a TCP/IP stack maintains and manages a context of the IP security. Accordingly, because another TCP/IP stack may not process an IP security packet, when transmitting a specific SIP message to which IP security is applied, a TCP/IP stack that manages the IP security context should be woken up. Even in a signaling procedure that may be processed by another TCP/IP stack, because the other TCP/IP stack does not have the IP security context, the other TCP/IP may not process the signaling procedure.
As described above, as a TCP/IP stack manages an IP security context, a message or a packet to which IP security is applied may be processed only by a corresponding TCP/IP stack. When a processor that controls the TCP/IP stack that manages the IP security context is always activated, problems are unlikely to occur. However, when the TCP/IP stack that manages the IP security context is in an idle state according to a predetermined condition, even if another TCP/IP stack is activated, the TCP/IP stack should finish an idle state.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.